• Journal of the Korean GEO-environmental Society
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• v.6 no.1
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• pp.73-82
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• 2005

Generally, to evaluate a slope stability of the geosynthetic reinforced soil slope, the modified version of limit equilibrium method can be used. In most cases, resisting effects of reinforcement are dealt with considering an increased shear strength on the potential slip surface. However, it is not clear that the methods satisfy all three equilibrium equations. In this study, the new slope stability analysis method in which not only reinforcing effects of geosynthetics can be considered but also all three equilibrium equation can be satisfied is proposed. A number of illustrative examples, including published load test of large-scale reinforced retaining wall and centrifuge model tests on the geotextile reinforced soil slopes, are also analyzed. As a result, it is shown that the newly suggested method produces a relatively accurate factor of safety.

• Journal of the Korean GEO-environmental Society
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• v.13 no.3
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• pp.29-37
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• 2012

This study is to find out the characteristics of the behavior of Geosyntehtic Reinforced Retaining Earth Wall(GRREW) through the laboratory experiment with the reduced-scale model, and to verify the effect of reinforcement by materials of GRREW. The loading tests after combining nonwoven geosynthetic, re-bar mesh nets and drainage blocks respectively among the components of the GRREW were performed in three cases of their slopes. In the cases of the behavior analysis including all of the components of the GRREW, the maximum horizontal displacement was generated 8.4mm at the location of 0.57H in the slope of 1:0.3; 3.8mm at the location of 0.57H in the slope of 1:0.6; 3.6mm at the location of 0.86H in the slope of 1:1.0. On average, the horizontal displacements of the GRREW were reduced by 83.8% against those of the original slopes. Lastly, seepage analysis and slope stability analysis were performed by modelling section of field, to confirm the effect of installation of drainage block in GRREW. We can confirm to compare increasing the slope safe factor and decreasing ground water in accordance with drainage blocks.

• Journal of the Korean Geosynthetics Society
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• v.16 no.4
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• pp.21-31
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• 2017

Geobag method is an eco-friendly method to minimize the impact on the environment in the construction of retaining wall structure as a kind of geosynthetic reinforced retaining walls. In this study, evaluated behavior of full scaled geobag retaining wall about four different types of geobag retaining walls, that is, non-compacted geobags wall, compacted geobag wall, combination of longitudinal and transversal laied geobags wall, gabion and geobag wall were constructed in the field with instrumentation. Based on the results of field measurement, transversal layered geobag wall for non-compacted case was displaced 30% more than that of mixed gabion wall. Also, the more than 2m geobag walls without reinforcement at the backfill area are turned out to be unstable in terms of wall displacement. On the one hand, the distribution of the earth pressure for all geobag retaining walls sites show within the range of Rankine's and Coulomb's earth pressure after construction. But after intensity rainfall, the transversal laied geobag walls significantly increment of soil pressure. The geobag walls which constructed in the way of mixed wall systems such as gabion and geobag, longitudinal and transversal laied geobags are much stable with comparison of transversal laied geobag wall.

• Journal of the Korean Geotechnical Society
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• v.15 no.1
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• pp.15-29
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• 1999

This study presents an analytical method of estimating the developed horizontal active thrusts against GRS-RW( Geosynthetic Reinforced Soil Retaining Wall) system adapted to the case of distanced surcharge. In addition, the design charts that could be used for preliminary design of GRS-RW system are presented. The proposed method of analysis uses two body translation mechanism as well as force polygon concept. taking into account the effect of facing's rigidity. Besides. the effect of tension cracks in c-\Phi$ soils, seismic effects and horizontal distance from the back face of wall to uniformly distributed surcharge loadings are also included. The results of horizontal active thrusts obtained from the developed method of analysis are compared with those from Jarquio's modified Boussinesq equation.

• Journal of the Korean Geosynthetics Society
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• v.4 no.3
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• pp.35-43
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• 2005

The geosynthetic reinforced segmental retaining walls(SRW) are improved that the disadvantage of existed retaining wall and the workability in field. Recently, the segmental retaining wall is replacing the exited wall because it is quickly advanced to using by the block in-situ. The use, therefore, is increasing. But, the trends of the large scaled construction was developed that the problems likely to crack and collapse, those are caused of careless in design and construction of SRW not considering about various surrounding conditions. In this study, the cause analysis on destructed SRW was carried out that based on the datum of measured displacement of walls, rainfall features and ground sounding conditions. Also, the analysis of the global slope stability was carried out on collapsed section and non-collapsed section using critical equilibrium method. For the rational stability and analysis of slope including SRW structure, the site conditions including situations of topography, ground and histories of construction and collapse etc should be considered. The rational countermeasure methods for non-collapsed and collapsed areas may be sustained as much as possible current state.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.508-517
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• 2018

This study evaluated the construction costs of 11 design cases to decrease the horizontal forces applied to an abutment. They include two kinds of abutment types, which are used to improve the backfill materials for reversed T-shaped abutment and geosynthehtic reinforced abutment for railways (RAR). In the first economic analysis, the internal friction angles of the backfill materials were increased from ${\Phi}=35^{\circ}$ to ${\Phi}=40^{\circ}$ and $50^{\circ}$ for a reversed T-shaped abutment. The second analysis examined cases with the design of a geosynthehtic RAR. When the friction angles were $40^{\circ}$ or $50^{\circ}$ after improvement of the backfill material, the reduction in the construction cost of the abutment was not as large (2.0-3.9%), even though the horizontal forces on the abutment were decreased by 18-48%. However, in the case of applying the RAR, a maximum cost reduction of 30% was achieved by decreasing the horizontal force to zero. The cost reduction results from the decreased wall thickness, base slab size, and the number of pile foundations for the abutment, as well as changing the material.

• Journal of the Korean Geosynthetics Society
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• v.11 no.4
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• pp.37-44
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• 2012

This paper describes large scale pullout test results, in order to evaluate extensibility effect of strip-type reinforcement. The same test for ribbed steel strip reinforcement also is conducted to compare the friction resistance reinforcements' evaluation results. The pullout resistance of the ribbed steel strip reinforcement, which has a small cross sectional areas, was better than the friction resistance reinforcements' due to the bearing (passive) resistance. In case of friction resistance reinforcements, the pullout resistance of extensible reinforcement was better than inextensible reinforcement' even though they have a similar cross sectional areas.

• Journal of the Korean Geotechnical Society
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• v.24 no.1
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• pp.71-80
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• 2008

This paper presents the reusults of wide width tensile tests under sustained and cyclic loads with vairous loading rate on geogrids. A seires of modified wide width tensile tests were conducted to investigate the effect of tensile strain rate on the deformation behavior of the geogrids. In addition, residual deformation characteristics of a geogrid under sustained or cyclic tests were also investigated. The results indicated that the residual deformation of a geogrid is strongly related to the viscous behavior of the geogrid, and the residual deformation can be well described by a hyperbolic curve. Also revealed was that residual deformation of a geogrid when subject to sustained or cyclic load should be described with the framework of viscous behavior.